The nutrients may not be available in certain soils, or may be present in forms that the plants cannot use. Soil properties like water content, pH, and compaction may exacerbate these problems.
Researchers used small samples of dust collected during ... The University of Florida team were given just 1g of soil per plant for the experiment from the samples, which have been kept locked ...
Mulches can also be used for decorating the tops of pots ... your chosen mulch and spread a 5cm (2in) layer around plants or across the soil with a spade, leaving a little gap around the stems ...